What Does Heirloom Really Mean?

Remember when none of us knew how to pronounce quinoa? Or when nobody knew what an açai berry was, and it was just another baffling smoothie add-in? What a time to be alive, when ancient grains and Amazonian berries are entering into mainstream lexicon!

But there's a downside: When a food becomes fashionable, suddenly it can feel tough to ask the most basic questions about what it is and how it came to be on our plates.

Luckily, we've got your back on terminology. And since it's peak tomato season, the time is ripe to get your facts straight about those Cherokee Purples and Black Krims.

Heirloom Tomatoes Are Like Granny's Good Silver

Visually speaking, heirlooms' varied shapes and colors set them apart from the conventional varieties you'll find piled up at the grocery store. But don't judge a tomato by its outward appearance: Not every homegrown, organic, or farmer's-market tomato is an heirloom.

The term "heirloom" is used to distinguish tomatoes that are grown with seeds "passed down" from generation to generation, generally over the course of 50 years or more. Think of heirloom tomatoes as akin to family heirlooms (say, your grandmother's good silver). If your beloved grandmother ever said, "They don't make them like they used to," she was right. Most modern fruits and vegetables don't resemble the ones your ancestors ate.

A Brief Lesson in Genetics: Open vs. Cross-Pollination

Another differentiating factor of heirloom produce is that it is open-pollinated. This means that the plant is pollinated by natural means (for example, by insects or wind).

By contrast, "hybrid" plants are the result of cross-pollination — the pollination of one species of plant with another — by humans. These hybrids can't be heirlooms for the simple reason that their genetic material is too variable. By cross-pollinating plants, you're not going to end up with a plant that's "true to type."

Which isn't to say that cross-pollination is bad and open-pollination is good. It's not that simple. Those heirlooms are, genetically speaking, inbred — Scientific American called them "the tomato equivalent of the pug" — and while they may taste just like the tomatoes your ancestors ate, their skins split easily, and they are uniquely unqualified to grapple with natural pathogens.

By comparison, modern varieties are heartier, more immune to disease. "As nitrogen fertilizers, cross-country transportation, and refrigeration greatly increased, so too did ways of producing food that strongly favor uniformity, durability, longevity, and transportability," Julia A. Jordan explains in her book Edible Memory: The Lure of Heirloom Tomatoes and Other Forgotten Foods.

So, Are Heirlooms Worth It?

Why, then, do we love these homely, fragile fruits? For one thing, just like family porcelain or a hand-stitched quilt, heirlooms are not something you can run out and buy in the store, which boosts their appeal as rare or precious specimens.

And then there's the taste factor. Compared to those durable, portable supermarket specimens, heirlooms are in a league of their own. Sure, there was something red on that BLT you ordered in February, but it was only a distant relative of the fruits they've been hawking at the farmers market lately: tomatoes that taste like — of all things — tomatoes.